ABSTRACT ? CORE B The mechanisms underlying the development, function, and regulation of regulatory B-cells (Bregs) and inflammatory B-effector (Beff) cells remain obscure. To date, studies of Bregs and Beff have been challenging due to their small numbers in clinical samples as well as their heterogeneity. However, the development of genomic approaches, such as RNA-Seq of bulk populations from low-input samples and single-cell RNA-Seq (scRNA-Seq) as well as CRISPR?Cas9 genome editing tools, now put this goal within reach. The Transcriptional and Perturbation Core at the Broad Institute will collaborate with all three projects of the PPG to profile samples using bulk RNA-Seq, single-cell RNA-Seq, and NanoString technology. We will perform computational analysis to generate circuit models and identify potential regulators and pathways involved in Breg and Beff regulation. We will test these predictive models by using CRISPR-Cas9 genome editing technology in primary cells. The Core will process and analyze samples across all projects and the resulting data will be shared among all the investigators of the PPG. Overall, these results will lead to better understanding of Breg and Beff biology, normal function, and their role in disease. It may also potentially lead to new avenues for therapy for autoimmunity, cancer, and transplant rejection.